Thermally stable amorphous magnetic alloy

ABSTRACT

During investigation of thermal stability of the amorphous magnetic alloys by the Inventors, it was discovered that, due to the application of heat to the alloys, the hysteresis loop of the conventional, amorphous magnetic alloys was shifted in such a manner that the initial permeability of the alloys was decreased. It was also discovered that the initial permeability of the conventional amorphous magnetic alloys was irreversibly changed due to the application of heat to and the withdrawal of heat from the alloys. 
     The present invention is characterized by the discovery of an unexpected relationship between the content of metallic elements and a metalloid element(s) of the amorphous alloy composition, thereby providing novel alloy compositions with thermally stable magnetic properties. 
     The present invention is also characterized by incorporating an additional element or elements into an amorphous magnetic alloy, thereby providing the alloy with thermal stability.

The present invention relates to an amorphous magnetic alloy.

Although metals are normally crystalline in the solid state, solidamorphous alloys having an atomic arrangement similar to as that in aliquid state can be obtained when a melt of specific kinds of alloys israpidly quenched at a high cooling rate ranging from 10⁴ to 10⁶ ° C. persecond and then solidified. Since the amorphous metal does not exhibitdiffraction patterns during X-ray diffraction measurements or electrondiffraction measurements, it can then be deduced that the atomicarrangement of the amorphous alloy is random and different from that ofthe crystalline metal.

In the U.S. Pat. application Ser. No. 656,864 now U.S. Pat. No.4,079,430 and German Laid-Open Specification No. 26 05 615, some of theInventors proposed a magnetic head, wherein the magnetic body thereof isan amorphous metal alloy of the general formula:

    M.sub.a Y.sub.b

wherein M is at least one metal selected from the group consisting ofiron, nickel and cobalt, Y is at least one element selected from thegroup consisting of phosphorous, boron, carbon and silicon, and whereinthe percentage of the components M and Y represented by the atomicpercentages in a and b are selected from the range of about 60 to about95 and from the range of 5 to 40, respectively, with the proviso that aplus b equals 100. In the Patent Application mentioned above, thefollowing amorphous alloys were tested:

    Fe.sub.80 P.sub.13 C.sub.7

    Fe.sub.45 Ni.sub.47 P.sub.8

    Co.sub.79 P.sub.21

    Fe.sub.80 P.sub.13 B.sub.7

    Fe.sub.40 Ni.sub.40 P.sub.14 B.sub.6.

After testing, the amorphous alloy having the formula M_(a) Y_(b) wasfound to have a low coercive force, a high initial permeability, a highelectric resistance and hardness, because the amorphous alloy did notexhibit magnetic anisotropy which is inherent in a normal crystal. Theamorphous alloy of the formula M_(a) Y_(b) was therefore found to besuited for use as a soft magnetic material.

The amorphous, magnetic alloys having the following compositions arealso known in the field of magnetic materials to have high initialpermeability.

    Fe.sub.4.7 Co.sub.70.3 Si.sub.15 B.sub.10

    Fe.sub.6 Co.sub.74 B.sub.20

The amorphous alloys having these known compositions and the amorphousalloys having the above-described tested composition disclosed in theU.S. patent application Ser. No. 656,864 were discovered by the presentInventors to have excellent magnetic properties only at around roomtemperature. When these amorphous alloys were heated for a few hours ata temperature of approximately 200° C., the initial permeability ofthese alloys measured after heating at room temperature was then reducedby 60 to 80% based on the permeability at room temperature beforeheating. Accordingly, the magnetic properties of these amorphous alloysare considered to be thermally unstable.

A person skilled in the art is aware that the initial permeability ofFe₅ Co₇₀ Si₁₅ B₁₀ at room temperature was reduced to one-sixth of itsinitial value by heating this alloy at 300° C.

The Inventors directed their attention to the importance of the thermalstability of the amorphous alloy, which is used as, for example, amagnetic head. By using the known amorphous alloys of Fe₄.7 Co₇₀.3 Si₁₅B₁₀ and Fe₆ Co₇₄ B₂₀, the present Inventors produced a magnetic head byusing the following procedures. The amorphous alloys were first formedinto sheets so as to reduce the eddy current loss of these alloys. Alarge number of the amorphous alloy sheets were laminated by placing abonding agent therebetween and then by heating at a temperature from 100to 200° C. A pair of the laminated sheets were shaped into a half ringform and coupled to one another by placing an insert therebetween. Thecoupled sheets were immersed in a resin, which was contained in acasing, and then, heated to approximately 100° C. for 3 hours, therebysecuring the sheets to the casing by the aid of the resin. As a resultof the heating, the initial permeability of the laminated amorphousalloy sheets was reduced from approximately 10,000 to values rangingfrom 2,000 to 3,000. Accordingly, the initial permeability of themagnetic head, i.e. the laminated sheets of the amorphous alloy, wasformed to be insufficient for using the sheets for a magnetic head.

It was also discovered by the present Inventors that the amorphousmagnetic alloys having the following compositions and used as softmagnetic materials, i.e. Fe₈₀ P₁₃ C₇, Fe₄₅ Ni₄₇ P₈, Co₇₉ P₂₁, Fe₈₀ P₁₃B₇, Fe₄₀ Ni₄₀ P₁₄ B₆, Fe₄.7 Co₇₀.3 Si₁₅ B₁₀, and Fe₆ Co₇₄ B₂₀, presentedsome serious problems, because the initial permeability of these alloycompositions decreases responsively depending upon the extent of thetemperature increase from room temperature, and furthermore, the valueof the decreased initial permeability cannot be restored to its originalvalue even after the temperature is decreased to the original roomtemperature. If these alloy compositions are used for producing amagnetic material, the material will not be satisfactory due to theabove-described irreversible decrease of the initial permeability.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an illustration of the change in hysterisis loop exhibited bya prior art alloy after heating at 200° C. for one hour.

FIG. 2 illustrates the relationship between the nickel content (C) andthe metalloid content (Y) of the alloys of the present invention.

FIG. 3 is a schematic representation of an apparatus for rapidly coolingthe alloys of the present invention to prepare them in an amorphousform.

FIG. 4 is an illustration of the effect of 5% of Mo on the variation ofinitial permeability with heating.

It is, therefore, an object of the present invention to provide athermally stable, amorphous magnetic alloy, which does not exhibit alarge reduction of the initial permeability when heated at a temperaturehigher than room temperature.

It is another object of the present invention to provide a thermallystable, amorphous magnetic alloy, which can be reliably made into anelectrical device, such as a magnetic head, by processing at atemperature which is higher than room temperature.

It is still another object of the present invention to provide anamorphous magnetic alloy which does not exhibit a large decrease orirreversible decrease of the initial permeability upon heating aboveroom temperatures.

As is known in this technical field, an amorphous alloy is changed to acrystalline alloy when heated to a high temperature. The reduction ofthe initial permeability by heating the amorphous alloy occurs, however,at a temperature considerably lower than the transition temperature atwhich the alloy changes from the amorphous state to the crystallinestate. The Inventors investigated the reason for the occurrence ofreduction of initial permeability at a temperature below thecrystallization temperature of the amorphous alloy by performing variousexperiments and discovered that, as shown in FIG. 1, the hysteresis loopof the amorphous alloy was shifted as seen in FIG. 1 by heating thealloy. In FIG. 1, the amorphous alloy of the composition (Fe₀.07 Co₀.85Ni₀.08)₇₅ Si₁₅ B₁₀ exhibits, prior to heating the alloy, the hyteresisloop denoted as 1, while the same alloy, after heating at 200° C. for anhour, exhibits the hysteresis loop denoted as 2. It is, therefore,apparent that the coercive force of the amorphous alloy was increased,i.e., shifted by several tens of mOe.

The present inventors, therefore, conducted research for preventing ashift of the hysteresis loop, as stated above, and unexpectedlydiscovered the following amorphous alloy.

An amorphous alloy, according to the present invention, is expressed bythe general formula:

    (Fe.sub.a Co.sub.b Ni.sub.c).sub.x (Si.sub.e B.sub.f).sub.y (1)

wherein, a, b and c are the molar fractions of iron, cobalt and nickel,respectively, with the proviso that a+b+c=1.00; e and f are the molarfractions of silicon and boron, respectively, with the proviso thate+f=1.00; x is the atomic percent of the iron, cobalt and nickel; and yis the atomic percent of the silicon and boron, based on the alloy,respectively; and further, the values a, c, e, f and y are limited toranges defined by the following relationships:

    0.03 >a≦0.12                                        (2)

    0≦c≦0.60                                     (3)

    27.5-8c≦y≦35-19C                             (4)

    0≦ey≦25, and                                 (5)

    0≦fy≦30.                                     (6)

The molar fractions mentioned above indicate the number of atoms foreach element, with the proviso that the total number of all of theelements in the group of either Fe, Co and Ni or in the group of Si andB be expressed by 1.0.

The above formula (4) indicates the relationship discovered by thepresent Inventors which exists between Ni and both Si and B. Both Si andB are known to help create an amorphous alloy state and may be referredto, hereinafter, as metalloid components. The relationship indicated byformula (4), according to a feature of the present invention, impliesthat when the Ni content (c) is decreased, the amount of the metalloidcomponents (y) should be increased. On the other hand, when the Niamount (c) is increased, the amount of the metalloid components (y)should be decreased.

The content of nickel (c) in the transition-metal components of nickel,cobalt and iron, should be from 0 to 0.60, according to formula (3), butshould perferably be from 0 to 0.30. When the nickel content (c) exceeds0.60, the saturation-magnetization of the amorphous alloy is too low.

FIG. 2 is a graph showing the composition range of an amorphous alloyaccording to the present invention, wherein the amount of the metalloidcomponents (y) is plotted on the abscissa and the nickel content (c) isplotted on the ordinate. In FIG. 2, the horizontal line determined bypoints (a) and (b), corresponds to a minimum nickel content (c) of 0,and the horizontal line determined by points (c) and (d) corresponds tothe maximum nickel content (c) of 0.60. The line determined by points(c) and (a) corresponds to the expression 27.5-8c of the formula (4),and the line determined by the points (d) and (b) corresponds to theexpression of 35-19c of the formula (4).

The area within the geometric Figure determined by the lines (a) (b),(b) (d), (d) (c), and (c) (a) corresponds to the amounts of nickel (Ni)and metalloid components (B and Si), wherein excellent magneticproperties of the amorphous alloy are provided. When y is smaller thanthe value determined by 27.5-c (line (a) (c), the magnetic properties ofthe amorphous alloy are quite thermally unstable. When y is larger thanthe value determined by 35-c (line (b) (d), the saturation magnetic fluxdensity of the amorphous alloy is insufficient for magnetic materialsand the magnetic properties of the amorphous alloy are quite thermallyunstable.

When the iron content (a), in terms of the molar fraction of thetransitional metal components of iron, cobalt and nickel, does not fallwithin the range of from 0.03 to 0.12, it is not possible to select theamorphous alloy composition within such a range that the magneticproperties of the alloy are maintained in a thermally stable state, and,further, the magnetostriction of the alloy is low. Due to the highmagnetostriction of the amorphous alloy having the composition notfalling within the above-mentioned range of 0.03 to 0.12, the initialpermeability of the alloy is decreased. As a result, the propertyrequired for a magnetic material is not provided by such an alloy.

Accordingly, a preferable iron content (a) for this alloy is that from0.04 to 0.09.

The content of silicon in the amorphous alloy should be from 0 to 25atomic % according to the above formula (5). However, the siliconcontent should preferably be from 5 to 20 atomic %. A silicon content of25 atomic % or lower helps to form an amorphous alloy structure and alsocontributes to increasing the wear resistance of the alloy. However,when the silicon content exceeds 25 atomic %, it then becomes difficultto produce an amorphous alloy in accordance with the present level ofthe known technique, because the presently obtainable cooling rate isgenerally from 10⁴ to 10⁶ ° C./second. In addition, when the siliconcontent exceeds 25 atomic %, the alloy becomes brittle.

The formula (6) indicates that the content (fy) of boron in theamorphous alloy should be within the range of from 0 to 30 atomic %,like silicon, a boron content of 30 atomic % or lower helps to form anamorphous alloy. However, when the boron content exceeds 30 atomic %, itis difficult to obtain an amorphous alloy, and the alloy becomesbrittle.

Preferred alloys with high initial permeability are as follows.

    (Fe.sub.0.07-0.08 Co.sub.0.62-0.63 Ni.sub.0.30).sub.71-73 (Si.sub.e B.sub.f).sub.27-29

    (Fe.sub.0.09-0.10 Co.sub.0.30-0.46 Ni.sub.0.45-0.60).sub.76-74 (Si.sub.e B.sub.f).sub.24-26

Another amorphous alloy according to the present invention is expressedby the general formula:

    (Fe.sub.a Co.sub.b Ni.sub.c).sub.x (Si.sub.e B.sub.f P.sub.g C.sub.h).sub.y,

wherein, a, b and c are the molar fractions of iron, cobalt and nickel,respectively, with the proviso that a+b+c=1.00; e, f, g and h are themolar fractions of silicon, boron, phosphorous and carbon, respectively,with the proviso that e+f+g+h=1.00; x is the atomic % of iron, cobaltand nickel; and y is the atomic % of silicon, boron, phosphorus andcarbon, and further, the values of a, c, e, f, g, h and y are limited toranges defined by the following relationships:

    0.03≦a≦0.12;                                 (2)

    0≦c≦0.60;                                    (3)

    27.5-8c≦y≦35 19c;                            (4)

    0≦ey≦25;                                     (5)

    0≦fy≦30, and;                                (6)

    0<(g+h)≦0.8(e+f).                                   (7)

The other amorphous alloy mentioned above is characterized by the factthat silicon and/or boron is partially replaced by either phosphorous orcarbon, or both, in an amount not exceeding 0.80, and preferably notexceeding 0.50 molar fraction based on the original total amount ofsilicon and boron.

Phosphorous and carbon which replace silicon and/or boron help to makean alloy amorphous. However, when the total contents of phosphorous andcarbon exceeds 28 atomic % based on the alloy, the saturation magneticflux density of the alloy is too low. In order to prevent a decrease inthe saturation magnetic flux density, the replaced amount should notexceed the above-mentioned 0.80 molar fraction.

Another amorphous magnetic alloy according to the present invention isexpressed by the general formula:

    (Fe.sub.a Co.sub.b Ni.sub.c).sub.x (Si.sub.e B.sub.f).sub.y,

wherein, a, b and c are the molar fractions of iron, cobalt and nickel,respectively, with the proviso that a+b+c=1.00; e and f are the molarfractions of silicon and boron, respectively, with the proviso thate+f=1.00; x and y are the atomic % of the iron, cobalt and nickel andthe silicon and boron, respectively, based on the above general formula,and, further, the values a, b, e, f and y are limited to range definedby the following relationships:

    0.03≦a≦0.12;                                 (8)

    0.40≦b≦0.85;                                 (9)

    20≦y≦35;                                     (10)

    0≦ey≦25, and;                                (11)

    0<fy≦30;                                            (12)

and, still further, at least one element selected from the groupconsisting of Ti, Zr, V, Nb, Ta, Cr, Mo, W, Zn, Al, Ga, In, Ge, Sn, Pb,As, Sb and Bi is added in an amount of from 0.5 to 6.0 atomic % based onthe total components of the amorphous alloy into the alloy expressed bythe general formula. In this group of elements Nb, Ta, W and In arepreferable, and Ge and Mo are more preferable.

The second alloy mentioned above has the characteristic feature whereinthe magnetic properties of the alloy are thermally stable and,particularly, the dependence of the initial permeability upontemperature at around room temperature is decreased and linear.

When the iron content (a), in terms of the molar fraction in thetransitional metal components of iron, cobalt and nickel, does not fallwithin the range of from 0.03 to 0.12, it is not possible to select thecomposition of the amorphous alloy within such a range that the magneticproperties of the alloy are maintained in a thermally stable state, and,further, the magnetostriction of the alloy is low. Due to highmagnetostriction of the amorphous alloy having the composition notfalling within the range of from 0.03 to 0.12, mentioned above, initialpermeability of the alloy is decreased. As a result, the propertyrequired for producing a magnetic material is not provided by such analloy. Accordingly, a preferable iron content for this alloy is thatfrom 0.04 to 0.09.

When the cobalt content (b), in terms of the molar fraction in thetransitional metal components of iron, cobalt and nickel, is smallerthan 0.40, the saturation magnetic flux density is decreased. On theother hand, when the cobalt content (b) exceeds 0.85, neither thermalstability nor the temperature dependence of the initial permeability isimproved by the addition of at least one of the elements selected fromthe group consisting of Ti, Zr, V, Nb, Ta, Cr, Mo, W, Zn, Al, Ga, In,Ge, Sn, Pb, As, Sb and Bi into the amorphous magnetic alloy. Apreferable cobalt content is from 0.40 to 0.70.

When the content (y), in terms of atomic % of the metalloid component,i.e. Si_(e) B_(f), is smaller than 20%, it becomes impossible to providean amorphous magnetic alloy with both thermal stability and an excellentdependence of the initial permeability upon temperature. On the otherhand, when the silicon content exceeds 25 atomic %, it then becomesdifficult to produce an amorphous alloy in accordance with the presentlevel of the known technique, because the presently obtainable coolingrate of a melt is generally from 10⁴ to 10⁶ ° C./second.

The content of silicon in the amorphous alloy should be from 0 to 25atomic % according to the formula (11). According, the silicon contentshould preferably be from 5 to 20 atomic %. A silicon content of 25atomic % or lower helps to form an amorphous alloy structure and alsocontributes to increasing the wear resistance of the alloy. However,when the silicon contents exceeds 25 atomic %, it then becomes difficultto produce an amorphous alloy. The amorphous magnetic alloy according tothe present invention may contain no silicon and instead includes onlyboron as the metalloid component. If the amount of boron to be includeddoes not exceed 30 atomic %, the boron can also help to form anamorphous alloy structure.

However, if the boron contents exceeds 30 atomic %, then it becomesdifficult to make an amorphous alloy and, in addition, the alloy becomesbrittle.

Elements such as Ti, Zr, V, Nb, Ta, Cr, Mo, W, Zn, Al, Ga, In, Ge, Sn,Pb, As, Sb and Bi, hereinafter referred to as additional elements,according to a feature of the present invention, suppress degradation ofthe magnetic properties of the amorphous alloy due to heating to atemperature lower than the crystallization temperature. When the alloyis heated to a temperature of approximately 100° C., these elementssuppress particularly the decrease of initial permeability of theamorphous alloy. These elements also suppress the irreversibility of theinitial permeability when the amorphous alloy is heated to a temperatureof approximately 100° C.

The atomic percent of the above-mentioned additional elements, such asTi, Zr and others, is based on the number of atoms of all of theelements Fe, Co, Ni, Si, B and the number of atoms of these additionalelements. If the content of the additional elements is smaller than 0.5atomic %, it is impossible to improve the thermal instability of themagnetic properties. On the other hand, if the contact of the additionalelements is greater than 6.0 atomic %, due to the increase of theadditional elements it becomes gradually impossible to provide the alloywith an amorphous structure. Furthermore, the saturation flux density isdecreased, with the result being that the magnetic properties of theamorphous alloy, are not sufficient for producing a magnetic material. Apreferable content of the additional elements is from 0.5 to 3 atomic %.

A further amorphous alloy according to the present invention isexpressed by the general formula:

    (Fe.sub.a Co.sub.b Ni.sub.c).sub.x (Si.sub.e B.sub.f P.sub.g C.sub.h).sub.y,

wherein, a, b and c are the molar fractions of iron, cobalt and nickel,respectively, with the proviso that a+b+c=1.00, e, f, g and h are themolar fractions of silicon, boron, phosphorous and carbon, respectively,with the proviso that e+f+g+h=1.00; x is the atomic % of the iron,cobalt and nickel; and y is the atomic % of the silicon, boron,phosphorous and carbon, and further, the values a, b, e, f, g and y arelimited to ranges defined by the following relationships:

    0.03≦a≦0.12;                                 (8)

    0.40≦b≦0.85;                                 (9)

    0≦ey≦25;                                     (13)

    0≦fy≦30, and;                                (14)

    0<(g+h)≦0.8 (e+f).                                  (15)

and, still further, at least one element selected from the groupconsisting of Ti, Zr, V, Nb, Ta, Cr, Mo, W, Zn, Al, Ga, ln, Ge, Sn, Pb,As, Sb and Bi is added in an amount from 0.5 to 6 atomic % based on thetotal components of the amorphous alloy into the alloy expressed by thegeneral formula. This alloy is characterized by the partial replacementof Si and/or B with P and/or C and by the inclusion of an additionalmetal into the amorphous alloy.

To distinguish an amorphous substance from a crystalline substance,X-ray diffraction measurement is generally employed. In this regard, anamorphous alloy produces a halo diffraction, but does not have sharpdiffraction peaks which are reflected from the lattice planes ofcrystals formed in an equilibrium state. It is, therefore, possible tocalculate the ratio of observed height of peaks with respect to thetheoretical height of the known standard peaks of crystals. The degreeof amorphousness is expressed in terms of this ratio. The amorphousalloy according to the present invention is essentially amorphous, sinceit has a degree of amorphousness of 50% or more and in preferred cases,75% or more.

A process for producing amorphous, magnetic alloys according to thepresent invention is hereinafter described. It is possible to producethermally stable, amorphous, magnetic alloys by super-rapidly cooling analloy melt, in a molten state to a solidified state at a cooling ratehigher than 10⁴ ° C./second.

FIG. 3 schematically illustrates an apparatus for carrying outsuper-rapid cooling of alloy from a molten state in order to produce anamorphous alloy. A quartz tube 1 is tapered at its lower end 1a. Thetapered lower end 1a functions as a nozzle for injecting a molten alloyinto the tube. An alloy specimen 2 is placed in the nozzle part 1a andmelted by a furnace 3. On the upper wall of the quartz tube 1 there isprovided an opening for introducing an inert gas, such as argon gas,into the tube at a low pressure. During melting, the inert gas preventsthe alloy specimen 2 from being oxidized. The rotatable metal roller 4for a super-rapid cooling of the molten metal is rotated by means of amotor 5, at a high speed equal to a circumferential speed of more than20 m/sec. The pneumatic piston 6 supports the quartz tube 1, and movesthe tube in a vertical direction.

The operation of the apparatus illustrated in FIG. 3 is performed asfollows. An alloy specimen is inserted from the upper end 8 into thelower end 1a of the quartz tube 1. The alloy specimen 2 is positioned atthe middle level of the furnace 3. Thereafter, the specimen 2 is wellmelted in an argon atmosphere, such argon being introduced into thequartz tube 1 provided with a nozzle through the opening 7. Thepneumatic piston 6 is then driven to lower the quartz tube 1 providedwith a nozzle at the end of the tube 1 into the position shown in FIG.3. The lower end of the nozzle is now positioned in the proximity of thecircumference of the high speed rotating roller 4. Subsequently, aninert gas of a high pressure is introduced from the upper end 8 into thequartz tube, for injecting a molten alloy onto the circumference of thehigh-speed rotating roller 4. The molten alloy is, consequently,super-rapidly cooled in order to obtain the desired amorphous alloy. Theresultant amorphous alloy is in the form of a ribbon having a thicknessof approximately 20 microns to 60 microns.

When heat is not applied to amorphous magnetic materials, the materialsexhibit no magnetic anisotropy, and thus exhibit high permeability. Theknown amorphous magnetic materials were, however, disadvantageous in thefact that the initial permeability of the materials was greatlydecreased due to heating the amorphous materials to a temperature offrom 100° to 200° C. According to the present invention, thedisadvantageous thermal instability of the amorphous materials isremoved. The magnetostriction of the amorphous alloy compositions can besuppressed to 1×10⁻⁶ or lower, because the alloy composition of thepresent invention exhibits thermally stable magnetic properties andfurther, all of the amorphous alloys exhibit no magnetic anisotropy. Itis therefore possible to provide a practical and employable softmagnetic material which exhibits excellent magnetic properties.

The amorphous magnetic materials according to the present invention canbe very suitably used as a magnetic head and a core for winding coiltherearound, a magnetic shield, an electromagnet, or the like. Theabove-listed devices may be employed in an electronic computer, imagetranscribing device, and card reader, a reed switch or audioapparatuses. The magnetic head, core, for winding a coil therearound,magnetic shield and electro magnet mentioned above can be advantageouslyproduced according to the present invention, without reducing themagnetic properties of the amorphous alloys. One process for producingsuch items comprises the steps of:

producing an amorphous magnetic alloy with one of its compositionschosen in accordance with the present invention, which alloy being inthe form of films;

laminating these films to the required thickness, by using a bondingagent, and;

heating the laminated films to a thermosetting temperature of a resin ofthe bonding agent;

such temperature ranging from approximately 100° to approximately 200°C.

The present invention is explained in more detail by means of thefollowing Examples.

EXAMPLE 1

Pure iron (purity of 99.9%), electrolytic cobalt (purity of 99.9%), Mondnickel (purity of 99.95%), silicon (purity of 99.99%) and crystallineboron were admixed in such an amount as to provide a composition of(Fe₀.08 Co₀.62 Ni₀.30)₇₃ Si₁₆ B₁₁, and melted in a Tammann furnace in anargon atmosphere. The melted alloy was sucked into a quartz tube andrapidly cooled to obtain a mother alloy. Subsequently, this mother alloywas rapidly cooled at a rate of approximately 10⁶ ° C./sec by using theapparatus illustrated in FIG. 3. The amorphous alloy specimens wereproduced in the form of a ribbon having a thickness of 40 microns. Thesespecimens were subjected to both X-ray diffraction and electrondiffraction. However, no diffraction pattern showing a crystal structureof the alloy was observed at all.

The resultant specimens were then wound one upon the other in a toroidalform to provide a core for winding coils. The initial magneticproperties of the core for winding coils were measured. After heatingthe core for winding coils to a temperature of 200° C. for one hour, themagnetic properties of the wound core were then measured at roomtemperature. The measurement results are shown in Table 1.

                                      Table 1                                     __________________________________________________________________________                                  Magnetic Flux                                                         Density at                                                     Initial        Shift of B-H                                                                          Magnetic                                        Condition of                                                                         Permeability                                                                         Coercive Force                                                                        Hysteresis loop                                                                       Field of                                        Specimen                                                                             μi(at 1KHz)                                                                       (Hc(mOe)                                                                              (mOe)   10/Oe/.B.sub.10 (G)                             __________________________________________________________________________    Initial                                                                       state  38,600 7       0       5,600                                           After                                                                         heating to                                                                    200° C. × 1h                                                            38,900 7       0       5,600                                           __________________________________________________________________________

As is clear from Table 1, the Specimen, (Fe₀.08 Co₀.62 Ni₀.30)₇₈ Si₁₆B₁₁, which contains 0.30 (molar fraction) of nickel and 27 atomic %,i.e., y=16+11, of the metalloid component, exhibits neither shift of itsB-H hysteresis loop nor decrease in its initial permeability due toheating of the Specimen to 200° C. for one hour. Accordingly, theamorphous magnetic alloy provided by the present invention is shown tobe thermally stable.

EXAMPLE 2

The procedure of Example 1 was repeated to produce amorphous alloys.These alloys exhibited compositional make-up which is almost free frommagnetostriction and which is based on iron, cobalt, nickel, silicon,and boron, occasionally phosphorous and/or carbon. The magneticproperties of the amorphous alloys are shown in Table 2, with regard toboth the initial state, i.e., as-quenched state, and the state afterheating to a temperature of 200° C. for one hour.

                                      Table 2                                     __________________________________________________________________________                      Initial Value     After Heating to 200° C. for 1                                         hour                                                                   Magnetic flux              Magnetic flux                                      density at            Shift                                                                              density at                              Initial    magnetic                                                                             Initial        B-H  magnetic                                permea-                                                                             Coercive                                                                           field of                                                                             permea-   Coercive                                                                           hysteresis                                                                         field of                                bility                                                                              force                                                                              10(Oe) bility                                                                              Δμi/μi                                                                force                                                                              loop 10/Oe                 No.                                                                              Composition    μi(1 KHz)                                                                        Hc(mOe)                                                                            B.sub.10 (G)                                                                         μi(1 kHz)                                                                        (%) Hc(mOe)                                                                            (mOe)                                                                              B.sub.10 (G)          __________________________________________________________________________     *1                                                                              (Fe.sub.0.06 Co.sub.0.94).sub.73 Si.sub.16 B.sub.11                                           9,620                                                                              23   7,600   1,250                                                                              -87.0                                                                             73   57   7,600                 2  (Fe.sub.0.05 Co.sub.0.95).sub.72.5 Si.sub.16.5 B.sub.11                                       9,850                                                                              21   7,200   9,940                                                                              + 9.1                                                                             21   0    7,200                 3  (Fe.sub.0.04 Co.sub.0.96).sub.69 Si.sub.18 B.sub.13                                          10,400                                                                              20   5,300  11,200                                                                              + 7.7                                                                             20   0    5,300                 4  (Fe.sub.0.03 Co.sub.0.97).sub.65 Si.sub.21 B.sub.14                                           9,350                                                                              24   3,200    9,440                                                                             + 9.6                                                                             23   0    3,200                 *5 (Fe.sub.0.08 Co.sub.0.72 NI.sub.0.20).sub.76 Si.sub.15 B.sub.9                                9,710                                                                              21   8,600   1,710                                                                              -82.4                                                                             61   38   ,8600                 6  (Fe.sub.0.07 Co.sub.0.73 Ni.sub.0.20).sub.74 Si.sub.16 B.sub.10                              13,600                                                                              19   7,500  12,900                                                                              - 5.1                                                                             19   0    7,500                 7  (Fe.sub.0.05 Co.sub.0.75 Ni.sub.0.20).sub.69 Si.sub.18 B.sub.13                              12,800                                                                              19   3,400  13,500                                                                              + 5.5                                                                             19   0    3,400                 *8 (Fe.sub.0.09 Co.sub.0.61 Ni.sub.0.30).sub.76 Si.sub.15 B.sub.9                               25,700                                                                              13   7,400   2,280                                                                              -91.1                                                                             54   29   7,400                 9  (Fe.sub.0.08 Co.sub.0.62 Ni.sub.0.30).sub.73 Si.sub.16 B.sub.11                              38,600                                                                              7    5,600  38,900                                                                              + 0.8                                                                             7    0    5,600                 10 (Fe.sub.0.07 Co.sub.0.63 Ni.sub.0.30).sub.71 Si.sub.17 B.sub.12                              42,900                                                                              6    3,500  43,600                                                                              + 1.6                                                                             6    0    3,500                 *11                                                                              (Fe.sub.0.11 Co.sub.0.44 Ni.sub.0.45).sub.73 Si.sub.13 B.sub.9                               11,400                                                                              20   6,500   2,070                                                                              -81.8                                                                             57   35   6,500                 12 (Fe.sub.0.10 Co.sub.0.45 Ni.sub.0.45).sub.76 Si.sub.15 B.sub.9                               36,200                                                                              8    5,200  35,800                                                                              + 1.1                                                                             8    0    5,200                 13 (Fe.sub.0.09 Co.sub.0.40 Ni.sub.0.45).sub. 74 Si.sub.16 B.sub.10                             47,500                                                                              6    3,200  46,900                                                                              - 1.3                                                                             6    0    3,200                 *14                                                                              (Fe.sub.0.12 Co.sub.0.28 Ni.sub.0.60).sub.78 Si.sub.13 B.sub.9                               16,300                                                                              17   4,500   1,930                                                                              -88.2                                                                             49   26   4,500                 15 (Fe.sub.0.11 Co.sub.0.20 Ni.sub.0.60).sub.77.3 Si.sub.13.7 B.sub.9                           32,500                                                                              9    3,800  32,200                                                                              - 0.9                                                                             9    0    3,800                 16 (Fe.sub.0.10 Co.sub.0.30 Ni.sub.0.60).sub.76.4 Si.sub.13.6 B.sub.10                          41,700                                                                              6    3,000  42,500                                                                              + 1.9                                                                             6    0    3,000                 17 (Fe.sub.0.08 Co.sub.0.62 Ni.sub.0.30).sub.73 Si.sub.10 B.sub.11               P.sub.6        35,700                                                                              8    5,400  36,900                                                                              + 2.2                                                                             8    0    5,400                 18 (Fe.sub.0.08 Co.sub.0.62 Ni.sub.0.30).sub.73 Si.sub.10 B.sub.11               C.sub.6        32,600                                                                              9    5,300  31,800                                                                              - 2.5                                                                             10   0    5,300                 19 (Fe.sub.0.08 Co.sub.0.62 Ni.sub.0.30).sub.73 Si.sub.10 B.sub.5 P.sub.6        C.sub.6        33,800                                                                              9    4,900  33,500                                                                              - 0.9                                                                             9    0    4,900                 20 (Fe.sub.0.08 Co.sub.0.62 Ni.sub.0.30).sub.73 B.sub.27                                        24,900                                                                              13   6,100  24,100                                                                              - 3.2                                                                             13   0    6,100                 21 (Fe.sub.0.08 Co.sub.0.62 Ni.sub.0.30).sub.73 Si.sub.7 B.sub.20                               29,300                                                                              11   5,900  28,500                                                                              - 2.7                                                                             11   0    5,900                 22 (Fe.sub.0.08 Co.sub.0.62 Ni.sub.0.30).sub.73 Si.sub.17 B.sub.16                              33,100                                                                              19   5,700  34,200                                                                              + 3.3                                                                             9    0    5,700                 23 (Fe.sub.0.03 Co.sub.0.62 Ni.sub.0.30).sub.73 Si.sub.20 B.sub.7                               40,700                                                                              7    5,400  41,600                                                                              + 2.2                                                                             6    0    5,400                 __________________________________________________________________________     Note:                                                                         Specimens with asterisk mark * do not fall within the scope of the presen     invention.                                                               

Specimens Nos. 1 through 4 correspond to the Fe--, Co--, Si--, B-- basedamorphous alloy which is free from Ni. In this alloy, when the totalamounts of the metalloid components of Si and B are 27.5 atomic % ormore, the alloy composition is thermally stable and shift of the B-Hhysteresis loop due to heating of the alloy does not occur within thiscomposition. However, when the total amounts of the metalloid componentexceeds 35 atomic %, the value of the magnetic flux density is too low,for example, lower than 3500 Gauss, with the result being that themagnetic properties of the alloy are insufficient for producing magneticmaterials. In the alloy free from Ni, thermally stable alloycompositions having excellent magnetic properties are provided when thetotal amount of metalloid components is from 27.5 to 35 atomic %,preferably from 27.5 to 32.0 atomic %.

Specimens Nos. 5 through 7 correspond to the Fe--, Co--, Ni--, Si-- andB-- based amorphous alloy containing 0.20 (molar fraction) of Ni. Inthis alloy composition, the alloy is thermally stable if the totalamount of the metalloid components is 26 atomic % or more, while themagnetic flux density level is too low if the total amount is more than31 atomic %. Accordingly, thermally stable alloy compositions havingexcellent magnetic properties are provided when the total amount of themetalloid components is from 26 to 31 atomic %, preferably from 26 to 30atomic %.

Specimens Nos. 11 through 13 correspond respectively to amorphous alloyscontaining 0.45 (molar fraction) of Ni. In this alloy composition, thealloy is thermally stable if the total amount of the metalloidcomponents is 24 atomic % or more, while the magnetic flux density levelis too low if the total amount is more than 31%. Accordingly, thermallystable alloy compositions having excellent magnetic properties areprovided when the total amount of the metalloid components is from 24 to26 atomic %, preferably from 24 to 25 atomic %.

Specimens Nos. 14 through 16 correspond respectively to amorphous alloyscontaining 0.60 (molar fraction) of Ni. In this alloy composition thealloy is thermally stable if the total amount of the metalloidcomponents is 22.7 atomic % or more, while the magnetic flux densitylevel is too low if the total amount is more than 23.6%. Therefore,thermally stable alloy compositions having excellent magnetic propertiesare provided if the total amount of the metalloid components is from22.7 to 23.6 atomic %, preferably from 23.0 to 23.6 atomic %. Thefollowing two relationships will be apparent from Specimens Nos. 1through 16. In order to provide an amorphous alloy with thermalstability, the relationship between the total amount of the metalloidcomponents and the content of nickel should be changed such that thetotal amount of the metalloid components is increased with a decrease inthe nickel content in the alloy system. Furthermore, in order to providethe amorphous alloy system with a magnetic flux density appropriate forproducing magnetic materials the relationship between the total amountof the metalloid components and the content of nickel should be changedsuch that the total amount of the metalloid components is decreased withan increase in the nickel content.

Specimens Nos. 17 through 19 correspond respectively to amorphous alloycompositions in which the Si or B is partially replaced with P and/or C.It is clear that by the partial replacement of Si or B with P and/or C,an excellent thermal stability of the amorphous alloy can be obtained.

Specimens Nos. 20 through 23 correspond respectively to the alloycompositions, in which the y value is equal to 27. In these specimens,the kind of metalloid components and the relative value of each of thesecomponents are respectively varied. Regardless of this variation, anexcellent thermal stability of the amorphous alloy can still beobtained.

EXAMPLE 3

The amorphous alloy according to the present invention having thecomposition (Fe₀.09 Co₀.65 Ni₀.26)₇₅ Si₁₅ B₁₀ with the 5% of Mo as wellas the control amorphous alloy having the composition (Fe₀.09 Co₀.65Ni₀.26)₇₅ Si₁₅ B₁₀ was produced by following the procedure of Example 1.The initial permeability of these alloys was measured under thefollowing condition wherein the temperature during measurement wasinitially -40° C., increased to 120° C. and then decreased to roomtemperature. The results of such measurement are shown in FIG. 4, inwhich the abscissa indicates the temperature during measurement and theordinate indicates a percentage variation of the measured initialpermeability with respect to that at room temperature. As is clear fromFIG. 4, the variation of the initial permeability is greater in thecontrol amorphous magnetic alloy (denoted as Control in FIG. 4) than inthe alloy of the present invention. In the control amorphous alloy, theinitial permeability is lower during the period for decreasing thetemperature during measurement from 120° C. than during the period forincreasing the temperature up to 120° C. during measurement.Furthermore, the initial permeability at 20° C. during the temperaturedecreasing period is more than 60% of that during the temperatureincreasing period. Namely, the initial permeability of the control alloyis not reversed to the original value after reversion of the temperatureduring measurement to 20° C. On the other hand, according to the presentinvention, the dependence of the initial permeability upon temperatureas well as the irreversible change of the initial permeability isessentially removed.

EXAMPLE 4

The procedure of Example 1 was repeated to produce amorphous alloycompositions, in which from 0 to 8 atomic % of Mo is added to the basiccomposition of (Fe₀.09 Co₀.65 Ni₀.26)₇₆ Si₁₅ B₁₀ by using a metallicmolybdenum with a purity of 99.9%. The results of the measurement of themagnetic properties are shown in Table 3.

                                      Table 3                                     __________________________________________________________________________    Initial Value            After Heating to 200° C. for 1 hour                            Magnetic flux                   Magnetic flux                                 density at              Shift of                                                                              density at                   Amount                                                                             Initial                                                                              Coercive                                                                           magnetic                                                                              Initial    Coercive                                                                           B-H hysteresis                                                                        magnetic                     of Mo                                                                              permeability                                                                         force                                                                              field of                                                                              permeability                                                                         Δμi/μi                                                                force                                                                              loop    field of                     (at %)                                                                             μi KHz)                                                                           HC(mOe)                                                                            10(Oe) B.sub.10 (G)                                                                   μi(1 KHz)                                                                         (%) Hc(mOe)                                                                            (mOe)   10/Oe/B.sub.10 (G)           __________________________________________________________________________    0    28,600 11   7,800    2,640 -90.8                                                                             53   31      7,800                        0.5  31,300 10   7,400   30,900 - 1.3                                                                             10   0       7,400                        1.0  33,700 9    6,800   32,500 - 3.6                                                                             9    0       6,800                        3.0  35,100 8    5,600   36,200 + 3.1                                                                             7    0       5,600                        5.0  34,900 8    4,200   33,700 - 3.4                                                                             9    0       4,200                        6.0  32,400 9    3,300   32,800 + 1.2                                                                             9    0       3,300                        8.0  30,500 10   1,900   31,600 + 3.6                                                                             10   0       1,900                        __________________________________________________________________________

From Table 3, it is apparent that by the addition of 0.5% or more of Mointo the amorphous alloy, a decrease of the initial permeability causedby the heating of the amorphous alloy is prevented from occurring, withthe result being that a thermally stable, amorphous magnetic material isprovided. When the added amount of Mo exceeds 6%, the magnetic fluxdensity of the amorphous alloy is found to be too low.

EXAMPLE 5

The procedure of Example 1 was repeated to produce amorphous alloycompositions, in which from 0 to 8 atomic % of Ge is added to the basiccomposition of (Fe₀.10 Co₀.55 Ni₀.35)₇₅ Si₁₅ B₁₀. The results of themeasurement of the magnetic properties are shown in Table 4.

                                      Table 4                                     __________________________________________________________________________    Initial value                                                                                        Dependence of Initial                                                                     After Heating to 200° C. for 1                                         hour                                                      Magnetic flux                                                                         Permeability upon          Shift                                                                              Magnetic flux          A-  Initial    density at                                                                            temperature Initial        B-H  density at             mount                                                                             permea-                                                                             Coercive                                                                           magnetic                                                                              Variation                                                                           Variation                                                                           Permea-   Coercive                                                                           hysteresis                                                                         magnetic               of Ge                                                                             bility                                                                              force                                                                              field of                                                                              at -40° C.                                                                   at +100° C.                                                                  bility                                                                              Δμi/μi                                                                force                                                                              loop field of               (at %)                                                                            μi(1 KHz)                                                                        Hc(mOe)                                                                            10(Oe) B.sub.10 (G)                                                                   (%)   (%)   μi(1 KHz)                                                                        (%) HC(mOe)                                                                            (mOe)                                                                              10/Oe/B.sub.10         __________________________________________________________________________                                                           (G)                    0   32,800                                                                              9    6,300   +44.1 -59.3 30,700                                                                              -6.4                                                                              10   16   6,300                  0.5 36,700                                                                              8    5,800   +38.6 -50.8 36,100                                                                              -1.6                                                                              8    0    5,800                  1.0 38,200                                                                              7    5,500   +35.2 -45.5 38,500                                                                              +0.8                                                                              7    0    5,500                  3.0 38,600                                                                              7    4,400   +27.5 -35.6 37,900                                                                              -1.8                                                                              7    0    4,400                  5.0 36,100                                                                              8    3,000   + 21.4                                                                              -27.3 36,800                                                                              +1.9                                                                              8    0    3,000                  8.0 31,400                                                                              10     900   +16.0 -21.2 30,600                                                                              -2.5                                                                              10   0      900                  __________________________________________________________________________

Since the Ni content of (Fe₀.10 Co₀.55 Ni₀.35)₇₅ Si₁₅ B₁₀ is higher thanthe Ni content of the alloy composition of Example 4, the Specimenwithout the Ge addition has a small B-H hysteresis loop shift afterheating. Since the magnetic properties of this Specimen cannot bedeteriorated by heating, it is possible to provide, without the additionof Ge, relatively stable magnetic properties for producing an amorphousmagnetic material. However, as is clear from Table 4, one of thefeatures of the addition of Ge to the amorphous alloy is that thedependence of the initial permeability upon temperature is decreasedwhen the amount of the added Ge is increased. It is, therefore, possibleto provide a further improved amorphous magnetic material, whichpossesses an excellent initial permeability which is dependent upon thetemperature.

EXAMPLE 6

The amount of several or all of the elements Fe, Co, Ni, Si, B and P, isdetermined to be such that the amorphous alloy compositions consistingof these elements are free from the effects of magnetostriction. Thesealloy compositions with or without an added element were produced byfollowing the procedure of Example 1. The magnetic properties of thesealloy compositions are shown in Table 5 with regard to the as-quenchedstate (designated as Initial Value in the Table) and the state afterheating to a temperature of 200° C. for one hour.

    Table 5      Initial Value After Heating to 200° C. for 1 hour   Magnetic     flux Dependence of     Magnetic flux   density at Initial    Shift     density at   magnetic permeability upon    of B-H magnetic Initial     Coercive field of temperature Initial  Coercive hystersis field of     permeability force 10(Oe) variatin variation permeability Δμi/.m     u.i force loop 10/Oe No. Composition μi(1 KHz) Hc(mOe) B.sub.10 (G)     at -40° C. at +100° C. μi(1 KHz) (%) Hc(mOe) (mOe)     B.sub.10      (G)                                                               *101     (Fe.sub.0.06 Co.sub.0.94).sub.75 Si.sub.15 B.sub.10  9,270 25 8,500 --     --  1,070 -88.5 75 63 8,500 *102 (Fe.sub.0.06 Co.sub.0.94).sub.75     Si.sub.15 B.sub.10 + Mo.sub.5 13,100 19 4,700 -- --  1,960 -85.0 59 35     4,700 *103 (Fe.sub.0.06 Co.sub. 0.94).sub.75 Si.sub.15 B.sub.10 +     Mo.sub.8 11,400 20 2,500 -- --      2,530 -77.8 42 29 2,500 *104 (Fe.sub.0.07 Co.sub.0.85      Ni.sub.0.08).sub.75 Si.sub.15 B.sub.10 11,200 20 9,200 -- --  1,630     -85.4 65 41 9,200 105 (Fe.sub.0.07 Co.sub.0.85 Ni.sub.0.08).sub.75     Si.sub.15 B.sub.10 + Mo.sub.5 12,600 19 5,300 +19.7 -26.0 11,800 - 6.3     20 0 5,400 106 (Fe.sub.0.07 Co.sub.0.85 Ni.sub.0.08).sub.75 Si.sub.15     B.sub.10 + Mo.sub.8 14,800 18 2,900 +11.3 -15.1 15,100 + 2.0 18 0 2,900     *107 (Fe.sub.0.08 Co.sub.0.75 Ni.sub.0.17).sub.75 Si.sub.15 B.sub.10     12,400 19 8,500 -- --  2,180 -82.4 58 36 8,500 108 (Fe.sub.0.08      Co.sub.0.75 Ni.sub.0.17).sub.75 Si.sub.15 B.sub.10 + Mo.sub.5 13,900 18     4,900 +20.5 -26.914,600 + 5.0 18 0 4,900 109 (Fe.sub.0.08 Co.sub.0.75     Ni.sub.0.17).sub.75 Si.sub.15 B.sub.10 + Mo.sub.8 15,100 18 2,700 +13.1     -17.8 14,500 - 4.0 18 0 2,700 *110 (Fe.sub.0.09 Co.sub.0.65      Ni.sub.0.26).sub.75 Si.sub.15 B.sub.10 28,600 11 7,800 -- --  2,640     -90.8 53 31 7,800 111 (Fe.sub.0.09 Co.sub.0.65 Ni.sub.0.26).sub.75     Si.sub.15 Bi.sub.10 + Mo.sub.5 34,900 8 4,200 +21.0 -27.1 33,700 - 3.4 9     0 4,200 112 (Fe.sub.0.09 Co.sub.0.65 Ni.sub.0.26).sub.75 Si.sub.15     B.sub.10 +Mo.sub.8 30,500 10 1,900 +14.5 -19.3 31,600 + 3.6 10 0 1,900     *113 (Fe.sub.0.11 Co.sub.0.40 Ni.sub.0.49).sub.75 Si.sub.15 B.sub.10     36,700 8 5,200 +48.3 -64.2 35,800 - 2.4 8 0 5,200 114 (Fe.sub.0.11     Co.sub.0.40 Ni.sub.0.49).sub.75 Si.sub.15 B.sub.10 + Mo.sub.1 38,200 7     4,500 +39.8 -51.4 38,400 + 0.5 7 0 4,500 115 (Fe.sub.0.11 Co.sub.0.40     Ni.sub.0.49).sub.75 Si.sub.15 B.sub.10 + Mo.sub.3 34,600 8 3,000 +25.7     -33.6 35,100+ 1.4 8 0 3,000 *116 (Fe.sub.0.12 Co.sub.0.65      Ni.sub.0.23).sub.80 Si.sub.12 B.sub.8 19,300 16 9,500 -- --  2,510     -87.0 57 34 9,500 117 (Fe.sub.0.12 Co.sub.0.65 Ni.sub.0.23).sub.80     Si.sub.12 B.sub.8 + Mo.sub.5 26,500 12 5,800 -- -- 24,900 - 6.0 13 0     5,800 118 (Fe.sub.0.12 Co.sub.0.65 Ni.sub.0.23).sub.80 Si.sub.12 B.sub.8     + Mo.sub.8 27,900 12 2,900 -- -- 27,500 -      1.4 12 0 2,900 *119 (Fe.sub.0.04 Co.sub.0.65 Ni.sub.0.31).sub.65     Si.sub.12 B.sub.14 36,100 8 5,300 -- -- 35,200 - 2.5 8 0 5,800 120     (Fe.sub.0.04 Co.sub.0.65 Ni.sub.0.31).sub.65 Si.sub.21 B.sub.14 +     Mo.sub.1 34,400 9 3,800 -- -- 35,400 + 2.9 8 0 3,800 121 (Fe.sub.0.09     Co.sub.0.65 Ni.sub.0.26).sub.75 Si.sub.15 B.sub.10 + Ti.sub.5 27,600 12     4,500 +17.9 -23.0 26,100 - 5.4 12 0 4,500 122 (Fe.sub.0.09 Co.sub.0.65     Ni.sub.0.26).sub.75 Si.sub.15 B.sub.10 + Zr.sub.5 26,300 12 4,300 +17.4     -22.3 25,200 - 4.2 13 0 4,300 123 (Fe.sub.0.09 Co.sub.0.65      Ni.sub.0.26).sub.75 Si.sub.15 B.sub.10 + V.sub.5 32,700 9 4,100 +20.1     -25.9 30,400 - 7.0 10 0 4,100 124 (Fe.sub.0.09 Co.sub.0.65      Ni.sub.0.26).sub.75 Si.sub.15 B.sub.10 + Nb.sub.5 31,000 10 4,200 +19.4     -24.9 31,700 + 2.2 10 0 4,200 125 (Fe.sub.0.09 Co.sub.0.65      Ni.sub.0.26).sub.75 Si.sub.15 B.sub.10 + Ta.sub.5 32,900 9 4,500 +20.2     -26.0 31,300 - 4.9 10 0 4,500 126 (Fe.sub.0.09 Co.sub.0.65      Ni.sub.0.26).sub.75 Si.sub.15 B.sub.10 + Cr.sub.5 30,100 10 4,400 +19.0     -24.4 29,600 - 1.7 11 0 4,400 127 (Fe.sub.0.09 Co.sub.0.65      Ni.sub.0.26).sub.75 Si.sub.15 B.sub.10 + W.sub.5 35,400 8 4,100 +21.4     -27.4 35,700 + 0.8 8 0 4,100 128 (Fe.sub.0.09 Co.sub.0.65      Ni.sub.0.26).sub.75 Si.sub.15 B.sub.10 + Zn.sub.5 31,700 10 4,300 +19.7     -25.3 30,600 - 3.5 10 0 4,300 129 (Fe.sub.0.09 Co.sub.0.65      Ni.sub.0.26).sub.75 Si.sub.15 B.sub.10 + Al.sub.5 33,800 9 4,100 +20.6     -26.5 32,900 - 2.7 10 0 4,100 130 (Fe.sub.0.09 Co.sub.0.65      Ni.sub.0.26).sub.75 Si.sub.15 B.sub.10 + Ga.sub.5 29,300 11 4,000 +18.7     -24.0 28,100 - 4.1 11 0 4,000 131 (Fe.sub.0.09 Co.sub.0.65      Ni.sub.0.26).sub.75 Si.sub.15 B.sub.10 + In.sub.5 27,500 12 4,200 +17.5     -23.0 26,400 - 4.0 12 0 4,200 132 (Fe.sub.0.09 Co.sub.0.65      Ni.sub.0.26).sub.75 Si.sub.15 B.sub.10 + Sn.sub.5 33,600 9 4,100 +20.5     -26.4 34,200 + 1.8 8 0 4,100 133 (Fe.sub.0.09 Co.sub.0.65      Ni.sub.0.26).sub.75 Si.sub.15 B.sub.10 + Pb.sub.5 27,700 12 4,200 +18.0     -23.1 26,300 - 5.0 13 0 4,200 134 (Fe.sub.0.09 Co.sub.0.65      Ni.sub.0.26).sub.75 Si.sub.15 B.sub.10 + As.sub.5 25,400 13 4,300 +17.0     -21.8 24,600 - 3.1 13 0 4,300 135 (Fe.sub.0.09 Co.sub.0.65      Ni.sub.0.26).sub.75 Si.sub.15 B.sub.10 + Sb.sub.5 23,900 14 4,200 +16.4     -21.0 25,100 + 5.0 13 0 4,200 136 (Fe.sub.0.09 Co.sub.0.65      Ni.sub.0.26).sub.75 Si.sub.15 B.sub.10 + Bi.sub.5 25,800 13 4,500 +17.2     -22.0 26,800 + 3.9 12 0 4,500 137 (Fe.sub.0.09 Co.sub.0.65      Ni.sub.0.26).sub.75 Si.sub.15 B.sub.10 + (Ti + Mo).sub.5 32,300 9 4,300     -- -- 31,500 - 2.5 10 0 4,300 138 (Fe.sub.0.09 Co.sub.0.65      Ni.sub.0.26).sub.75 Si.sub.15 B.sub.10 + (Ta + Al).sub.5 29,100 11     4,200 -- -- 30,300 + 4.1 11 0 4,200 139 (Fe.sub.0.09 Co.sub.0.65     Ni.sub.0.26).sub.75 Si.sub.15 B.sub.10 + (Nb + Ge).sub.5 33,500 9 4,600     -- -- 34,400 + 2.7 9 0 4,600 140 (Fe.sub.0.09 Co.sub.0.65      Ni.sub.0.26).sub.75 Si.sub.15 B.sub.10 + (W + Sb).sub.5 27,400 12 4,400     -- -- 29,700 + 8.4 11 0 4,400 141 (Fe.sub.0.09 Co.sub.0.65      Ni.sub.0.26).sub.75 Si.sub.15 B.sub.10  + (Cr + Sn).sub.5 34,200 9     4,700 -- -- 32,900 - 3.8 9 0 4,700 142 (Fe.sub.0.09 Co.sub.0.65      Ni.sub.0.26).sub.75 B.sub.25 + Mo.sub.5 21,300 15 5,100 -- -- 20,600 -     3.3 15 0 5,100 143 (Fe.sub.0.09 Co.sub.0.65 Ni.sub.0.26).sub.75 Si.sub.5     B.sub.20 + Mo.sub.5 26,800 12 4,800 -- -- 25,700 - 4.1 12 0 4,800 144     (Fe.sub.0.09 Co.sub.0.65 Ni.sub.0.26).sub.75 Si.sub.10 B.sub.15 +     Mo.sub.5 32,500 9 4,500 -- -- 33,800 + 4.0 9 0 4,500 145 (Fe.sub.0.09     Co.sub.0.65 Ni.sub.0.26).sub.75 Si.sub.20 B.sub.5 + Mo.sub.5 21,400 15     4,100 -- -- 21,100 - 1.4 15 0 4,100 146 (Fe.sub.0.09 Co.sub.0.65     Ni.sub.0.26).sub.75 Si.sub.8 B.sub.10 P.sub.5 + Mo.sub.5 28,500 11 4,300     -- -- 29,300 + 2.8 11 0 4,300 147 (Fe.sub.0.09 Co.sub.0.65      Ni.sub.0.26).sub.75 Si.sub.8 B.sub.5 P.sub.7 C.sub.5 +  Mo.sub.5 27,300     12 4,500 -- -- 26,500 -     Note:     .sup.1 Variation of the initial permeability depending upon the     temperature indicates variation with respect to the initial permeability     at 20° C. as the standard.     .sup.2 Specimens with an asterisk mark (*) do not fall within the scope o     the present invention.

The following facts will be apparent from Table 5.

(1) The B-H hysteresis loop shifts due to the heating of the alloycomposition in the following cases. Namely, the amount of Co (b) is 0.94(Samples 102 and 103), and none of the additive metals is added (Samples101, 107, 113, 116 and 119).

(2) The hysteresis loop is not shifted and both the value Δμi/μi and thedependence of the initial permeability upon temperature are low when oneor more of additive metals are used.

(3) The effects of the use of additive metals, described in item (2),above, are substantially the same with regard to different kinds ofadditive metals.

(4) The magnetic flux density is decreased to a relatively low value,but the initial permeability can be increased, when the added amount ofMo is as high as 8 atomic %.

(5) From the comparisons of Specimens Nos. 122 through 136 with oneanother, the effects of the additive elements are found to besubstantially the same, except that the effects on the initialpermeability μi and Δμi/μi are slightly different between these additiveelements. W and Sn are the primary preferable elements, and Cr and Nbare the secondary preferable elements in the additive metals, from apoint of view of initial permeability.

(6) When the Co content is lower than 0.70, the initial permeability ishigh. Therefore, it desirable that the Co content for the amorphousmagnetic material with high permeability be in the range of from 0.40 to0.70.

What we claim is:
 1. An essentially amorphous, magnetic alloy havingstable magnetic properties after heating to a temperature in the rangeof 100° to 200° C. said alloy having the general formula:

    (Fe.sub.a Co.sub.b Ni.sub.c).sub.x (Si.sub.e B.sub.f).sub.y,

wherein, a, b and c are the molar fractions of iron, cobalt and nickel,respectively, wherein a+b+c=1.00; e and f are the molar fractions ofsilicon and boron, respectively, wherein e+f=1.00; x is the atomicpercent of iron, cobalt and nickel; and y is an atomic percent ofsilicon and boron, based on the alloy, respectively, and, wherein a, c,e, f and y are defined by the following relationships:

    0.03≦a≦0.12

    0≦c≦0.60

    27.5-8c≦y≦35-19c

    0≦ey≦25, and

    0≦fy≦30.


2. An alloy according to claim 1, wherein said values a, c, e and y aredefined by the following relationships:

    0.04≦a≦0.09

    0≦c≦0.30, and

    5≦ey≦20.


3. An essentially amorphous, magnetic alloy having stable magneticproperties after heating to a temperature in the range of 100° to 200°C. said alloy having the general formula:

    (Fe.sub.a Co.sub.b Ni.sub.c).sub.x (Si.sub.e B.sub.f P.sub.g C.sub.h).sub.y,

wherein, a, b and c are the molar fractions of iron, cobalt and nickel,respectively, wherein a+b+c=1.00; e, f, g and h are the molar fractionsof silicon, boron, phosphorous and carbon, respectively, whereine+f+g+h=1.00; x is the atomic % of iron, cobalt and nickel; and y is theatomic % of silicon, boron, phosphorous and carbon based on the alloy,respectively and, a, c, e, f, g and h and y are defined by the followingrelationships:

    0.03≦a≦0.12;

    0≦c≦0.60;

    27.5-8c≦y≦35-19c;

    0≦ey≦25;

    0≦fy≦30, and;

    0<(g+h)<0.8(e+f).


4. An alloy according to claim 3, wherein a, c, e, y, g and h aredefined by the following relationships:

    0.04≦a≦0.09

    0≦c≦0.30

    5≦ey≦20, and

    0<(g+H)<0.5(e+f).


5. An essentially amorphous magnetic alloy having stable magneticproperties after heating to a temperature in the range of 100° to 200°C. and which has a reduced irreversible dependence of the initialpermeability over a temperature range of -40° C. to 120° C., said alloyhaving the general formula:

    (Fe.sub.a Co.sub.b Ni.sub.c).sub.x (Si.sub.e B.sub.f).sub.y,

wherein, a, b and c are the molar fractions of iron, cobalt and nickel,respectively, wherein a+b+c=1.00; e and f are the molar fractions ofsilicon and boron, respectively, wherein e+f=1.00; x is the atomic % ofiron cobalt and nickel and y is the atomic % of silicon and boron,respectively, based on the composition expressed by said generalformula, and, further, said values a, b, e, f and y are defined by thefollowing relationships:

    0.03≦a≦0.12;

    0.40≦b≦0.85;

    20≦y≦35;

    0≦ye≦25, and;

    0<fy≦30;

and, wherein at least one element selected from the group consisting ofTi, Zr, V, Nb, Ta, Cr, Mo, W, Zn, Al, Ga, In, Ge, Sn, Pb, As, Sb and Biin an amount from 0.5 to 6.0 atomic % based on the total components ofthe amorphous alloy is present in said alloy expressed by said generalformula.
 6. An alloy according to claim 5, wherein said values a, b, eand y are defined by the following relationships:

    0.04≦a≦0.09

    0.40≦b≦0.70, and

    5≦ey≦20,

and the content of said at least one element is from 0.5 to 3.0 atomic%.
 7. An essentially amorphous, magnetic alloy having stable magneticproperties after heating to a temperature in the range of 100° to 200°C. and which has a reduced irreversible dependence of the initialpermeability over a temperature range of -40° C. to 120° C. said alloyhaving the general formula:

    (Fe.sub.a Co.sub.b Ni.sub.c).sub.x (Si.sub.e B.sub.f P.sub.g C.sub.h).sub.y,

wherein, a, b and c are the molar fractions of iron, cobalt and nickel,respectively, wherein a+b+c=1.00; e, f, g and h are the molar fractionsof silicon, boron, phosphorous and carbon, respectively, whereine+f+g+h=1.00; x is the atomic % of iron, cobalt and nickel; and y is theatomic % of silicon, boron, phosphorous and carbon based on the alloyrespectively, and said values a, c, e, f, g, h and y are defined by thefollowing relationships:

    0.03≦a≦0.12;

    0.40≦b≦0.85;

    0≦ey≦25;

    0≦fy≦30, and;

    0<(g+h)≦0.8(e+f),

and, wherein at least one element selected from the group consisting ofTi, Zr, V, Nb, Ta, Cr, Mo, W, Zn, Al, Ga, In, Ge, Sn, Pb, As, Sb and Biin an amount from 0.5 to 6.0 atomic % based on the total components ofthe amorphous alloy is present in said alloy expressed by said generalformula.
 8. An alloy according to claim 7, wherein said values a, b, e,y, g and h are defined by the following relationships:

    0.04≦a≦0.09

    0.40≦b≦0.70

    5≦ey≦20

    0<(g+h)≦0.50(e+f),

and the content of said at least one element is form 0.5 to 3.0 atomic%.
 9. Alloys of claim 1 of the formula

    (Fe.sub.0.07-0.08 Co.sub.0.62-0.63 Ni.sub.0.30).sub.71-73 (Si.sub.e B.sub.f).sub.27-29

wherein e and f are the molar fractions of Si and B, respectively. 10.Alloys of claim 1 of the formula

    (Fe.sub.0.09-0.10 Co.sub.0.30-0.46 Ni.sub.0.45-0.60).sub.76-74 (Si.sub.e B.sub.f).sub.24-26

wherein e and f are the molar fractions of Si and B, respectively. 11.An alloy of claim 1 of the formula

    (Fe.sub.0.05 Co.sub.0.95).sub.72.5 Si.sub.16.5 B.sub.11


12. An alloy of claim 1 of the formula

    (Fe.sub.0.04 Co.sub.0.96).sub.69 Si.sub.18 B.sub.13


13. An alloy of claim 1 of the formula

    (Fe.sub.0.03 Co.sub.0.97).sub.65 Si.sub.21 B.sub.14


14. An alloy of claim 1 of the formula

    (Fe.sub.0.07 Co.sub.0.73 Ni.sub.0.20).sub.74 Si.sub.16 B.sub.10


15. An alloy of claim 1 of the formula

    (Fe.sub.0.05 Co.sub.0.75 Ni.sub.0.20).sub.69 Si.sub.18 B.sub.13


16. An alloy of claim 1 of the formula

    (Fe.sub.0.08 Co.sub.0.62 Ni.sub.0.30).sub.73 Si.sub.16 B.sub.11


17. An alloy of claim 1 of the formula

    (Fe.sub.0.07 Co.sub.0.63 Ni.sub.0.30).sub.71 Si.sub.17 B.sub.12


18. An alloy of claim 1 of the formula

    (Fe.sub.0.10 Co.sub.0.45 Ni.sub.0.45).sub.76 Si.sub.15 B.sub.9


19. An alloy of claim 1 of the formula

    (Fe.sub.0.09 Co.sub.0.40 Ni.sub.0.45).sub.74 Si.sub.16 B.sub.10


20. An alloy of claim 1 of the formula

    (Fe.sub.0.11 Co.sub.0.20 Ni.sub.0.60).sub.77.3 Si.sub.13.7 B.sub.9


21. An alloy of claim 1 of the formula

    (Fe.sub.0.10 Co.sub.0.30 Ni.sub.0.60).sub.76.4 Si.sub.13.6 B.sub.10


22. An alloy of claim 3 of the formula

    (Fe.sub.0.08 Co.sub.0.62 Ni.sub.0.30).sub.73 Si.sub.10 B.sub.11 P.sub.6


23. An alloy of claim 3 of the formula

    (Fe.sub.0.08 Co.sub.0.62 Ni.sub.0.30).sub.73 Si.sub.10 B.sub.11 C.sub.6


24. An alloy of claim 3 of the formula

    (Fe.sub.0.08 Co.sub.0.62 Ni.sub.0.30).sub.73 Si.sub.10 B.sub.5 P.sub.6 C.sub.6


25. An alloy of claim 1 of the formula

    (Fe.sub.0.08 Co.sub.0.62 Ni.sub.0.30).sub.73 B.sub.27


26. An alloy of claim 1 of the formula

    (Fe.sub.0.08 Co.sub.0.62 Ni.sub.0.30).sub.73 Si.sub.7 B.sub.20


27. An alloy of claim 1 of the formula

    (Fe.sub.0.08 Co.sub.0.62 Ni.sub.0.30).sub.73 Si.sub.17 B.sub.16


28. An alloy of claim 1 of the formula

    (Fe.sub.0.03 Co.sub.0.62 Ni.sub.0.30).sub.73 Si.sub.20 B.sub.7


29. Alloys of claim 5 of the formula

    (Fe.sub.0.07 Co.sub.0.85 Ni.sub.0.08).sub.75 Si.sub.15 B.sub.10 Mo.sub.5-8


30. Alloys of claim 5 of the formula

    (Fe.sub.0.08 Co.sub.0.75 Ni.sub.0.17).sub.75 Si.sub.15 B.sub.10 Mo.sub.5-8


31. Alloys of claim 5 of the formula

    (Fe.sub.0.09 Co.sub.0.75 Ni.sub.0.26).sub.75 Si.sub.15 B.sub.10 Mo.sub.5-8


32. Alloys of claim 5 of the formula

    (Fe.sub.0.11 Co.sub.0.40 Ni.sub.0.49).sub.75 Si.sub.15 B.sub.10 Mo.sub.1-3


33. Alloys of claim 5 of the formula

    (Fe.sub.0.12 Co.sub.0.65 Ni.sub.0.23).sub.80 Si.sub.12 B.sub.8 Mo.sub.5-8


34. An alloy of claim 5 of the formula

    (Fe.sub.0.04 Co.sub.0.65 Ni.sub.0.31).sub.65 Si.sub.21 B.sub.14 Mo.sub.1


35. Alloys of claim 5 of the formula

    (Fe.sub.0.09 Co.sub.0.65 Ni.sub.0.26).sub.75 Si.sub.15 B.sub.10 Z.sub.5

wherein Z is an element selected from the group consisting of Ti, Zr, V,Nb, Ta, Cr, W, Zn, Al, Ga, In, Sn, Pb, As, Sb and Bi.
 36. Alloys ofclaim 5 of the formula

    (Fe.sub.0.09 Co.sub.0.65 Ni.sub.0.26).sub.75 Si.sub.15 B.sub.10 X.sub.5

wherein X is a combination of elements selected from the groupconsisting of (Ti+Mo), (Ta+Al), (Nb+Ge), (W+Sb) and (Cr'Sn).
 37. Analloy of claim 5 of the formula

    (Fe.sub.0.09 C.sub.0.65 Ni.sub.0.26).sub.75 B.sub.25 Mo.sub.5


38. An alloy of claim 5 of the formula

    (Fe.sub.0.09 Co.sub.0.65 Ni.sub.0.26).sub.75 Si.sub.5 B.sub.20 Mo.sub.5


39. An alloy of claim 5 of the formula

    (Fe.sub.0.09 Co.sub.0.65 Ni.sub.0.26).sub.75 Si.sub.10 B.sub.15 Mo.sub.5


40. An alloy of claim 5 of the formula

    (Fe.sub.0.09 Co.sub.0.65 Ni.sub.0.26).sub.75 Si.sub.20 B.sub.5 Mo.sub.5


41. An alloy of claim 7 of the formula

    (Fe.sub.0.09 Co.sub.0.65 Ni.sub.0.26).sub.75 Si.sub.8 B.sub.10 P.sub.5 Mo.sub.5


42. An alloy of claim 7 of the formula

    (Fe.sub.0.09 Co.sub.0.65 Ni.sub.0.26).sub.75 Si.sub.8 B.sub.5 P.sub.7 C.sub.5 Mo.sub.5